Biochemical studies on proteins of the lumbar spinal cord, ventral roots and isolated spinal motoneurons are to be performed on frogs whose 9th and 10th ventral roots have been transected. Neurotransmitter-related enzymes and structural proteins will be examined for alterations in activity, mass, and relative rates of synthesis and degradation. These studies should help elucidate the biochemical mechanisms by which spinal motoneurons respond to injury of their axons.